Re: [Int-area] Apps Directorate Review of draft-ietf-intarea-ipv4-id-update-05

["C. M. Heard" <[e-mail]>]

On Sat, 2 Jun 2012, Joe Touch wrote:
> Hi, Eliot,
> 
> On Jun 2, 2012, at 6:00 AM, Eliot Lear wrote:
> 
> > 
> > Document: draft-ietf-intarea-ipv4-id-update-05
> > Title: Updated Specification of the IPv4 ID Field
> > Reviewer: Eliot Lear
> > Review Date: 2 June 2012
> > IETF Last Call Date: 31 May  2012
> > 
> > 
> > Summary: This draft is quite well written, and is very nearly ready for publication.
> > 
> > This draft is well written, and from the applications 
> > perspective represents an important step to improving 
> > performance and error reduction.  It uses a new requirements 
> > call-out style that I would class as experimental, but not bad.  
> > It is worth people reading this draft and deciding if they agree 
> > with Joe's approach.

FWIW, I thought it was helpful.

> > Major issues:
> > 
> > None (Yay!).
> > 
> > Minor issues:
> > 
> > Section 4 needs to be reconciled a bit with Section 6.1.  Specifically:
> > 
> >>  The IPv4 ID field can be useful for other purposes. 
> > 
> > 
> > And
> > 
> >   >> IPv4 ID field MUST NOT be used for purposes other than
> >    fragmentation and reassembly.
> > 
> > 
> > My suggestion is to drop the above sentence from Section 4.
> 
> The two are not contradictory - the ID can be useful, but 
> generating it correctly is prohibitive and typically not done.

After re-reading the text I agree with Eliot that it is confusing.  
Dropping the sentence in Section 4 would be fine.  Another 
possibility would be to reword it along the following lines:

  Other uses have been envisioned for the IPv4 ID field.

> > In Section 6.1:
> > 
> > 
> >>    Datagram de-duplication can be accomplished using hash-based
> >>    duplicate detection for cases where the ID field is absent.
> >> 
> > 
> > Under what circumstances would the ID field be absent?
> 
> Replace "absent" with "known not unique".

Better, I think, would be "not known to be unique".

> >>    >> Sources of non-atomic IPv4 datagrams using strong integrity checks
> >>    MAY reuse the ID within MSL values smaller than is typical.
> >> 
> > 
> > Is the issue really the source using strong integrity checks or 
> > the destination in this context?  What is typical?
> 
> The onus is on the source (of non-atomic datagrams) - if it 
> includes strong integrity checks (that are presumably validated by 
> the receiver), it then has more flexibility in its generation of 
> the iD values.
> 
> > Nit:
> > 
> > Shouldn't Sections 3, 4, and 5, really be Sections 2.1, 2.2, and 2.3?
> 
> Not subsections of 2, but perhaps "3, 3.1, 3.2"?

That would be fine but I'm also OK with leaving the document the way 
it is (especially if it would get it into the publication queue 
faster).

//cmh